Ok so I have never written a review before, but I just had to for this! I am 5' and weigh about 105lbs. I first ordered the s/m thinking it would be too big, I typically wear xxs or xs. Boy was I wrong! By the way I don't have a butt at all and my breast size is a small B. This bathing suit may fit your toddler. So I returned the s/m and ordered the m/l thinking surely this will do, wrong again, pretty sure that they just switched the label. I am now very curious about the dimensions of the model in the photo, was this custom made or what?!? Perhaps it shrunk in the mail! So, now I will be returning the m/l too.